The Histology and Imaging core supports analysis of mutant ears and connectional defects at all levels in fixed tissue. The goal of this core is to provide the necessary training and certain services to process and image ears at all light and electron microscopic levels, including high resolution multiphoton imaging using multicolor labeling and 3D reconstruction to accelerate analysis of existing and soon to be analyzed mutants or otherwise manipulated ears, including samples of human ears as needed. To this end, the core provides expertise through the core personnel, including a full time RA expertly trained in all techniques needed to evaluate ears and neuronal connections at all stages of development. Reservation of the equipment in this core (three confocal systems, high resolution transmitted and epifluorescence microscopes and dissecting scopes, TEM and SEM, freezing microtomes, vibratomes and ultramicrotomes) will be handled on line. The specific aims of the histology and imaging core are: (1) To provide a range of service (advice and/or assistance) for optimized and standardized histological processing at all levels of light and electron microscopy, including sophisticated multicolor immunocytochemical labeling followed by multiphoton analysis, or combinations of in situ hybridization and immunocytochemistry; (2) To improve data analysis through the availability and use of appropriate image processing and quantitative analysis software; (3) To provide expert training in these techniques to stimulate collaboration between members of the core grant as well as potential additional members currently funded through NIDCD. The histology core closely interacts with other cores such as the molecular core for the generation of in situ probes. The core will be driven by the needs of several researchers to achieve a standardized high resolution analysis of various mouse models generated by genetic or other manipulations. The scientific expertise of the core personnel will enhance the performance of all core related research. An annual workshop that provides overviews of the techniques available in this core and their potential usefulness for research of current and future members of the core will generate a vital interaction toward a hearing research related community at the Univ. of Iowa.